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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_AccessibleCaretEventHub_h
+#define mozilla_AccessibleCaretEventHub_h
+
+#include "LayoutConstants.h"
+#include "mozilla/EventForwards.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/WeakPtr.h"
+#include "nsCOMPtr.h"
+#include "nsDocShell.h"
+#include "nsIReflowObserver.h"
+#include "nsIScrollObserver.h"
+#include "nsPoint.h"
+#include "mozilla/RefPtr.h"
+#include "nsWeakReference.h"
+
+class nsITimer;
+
+namespace mozilla {
+class AccessibleCaretManager;
+class PresShell;
+class WidgetKeyboardEvent;
+class WidgetMouseEvent;
+class WidgetTouchEvent;
+
+// -----------------------------------------------------------------------------
+// Each PresShell holds a shared pointer to an AccessibleCaretEventHub; each
+// AccessibleCaretEventHub holds a unique pointer to an AccessibleCaretManager.
+// Thus, there's one AccessibleCaretManager per PresShell.
+//
+// AccessibleCaretEventHub implements a state pattern. It receives events from
+// PresShell and callbacks by observers and listeners, and then relays them to
+// the current concrete state which calls necessary event-handling methods in
+// AccessibleCaretManager.
+//
+// We separate AccessibleCaretEventHub from AccessibleCaretManager to make the
+// state transitions in AccessibleCaretEventHub testable. We put (nearly) all
+// the operations involving PresShell, Selection, and AccessibleCaret
+// manipulation in AccessibleCaretManager so that we can mock methods in
+// AccessibleCaretManager in gtest. We test the correctness of the state
+// transitions by giving events, callbacks, and the return values by mocked
+// methods of AccessibleCaretEventHub. See TestAccessibleCaretEventHub.cpp.
+//
+// Besides dealing with real events, AccessibleCaretEventHub could also
+// synthesize fake long-tap events and inject those events to itself on the
+// platform lacks eMouseLongTap. Turn on this preference
+// "layout.accessiblecaret.use_long_tap_injector" for the fake long-tap events.
+//
+// Please see the in-tree document for state transition diagram and more
+// information.
+// HTML: https://firefox-source-docs.mozilla.org/layout/AccessibleCaret.html
+// Source rst: layout/docs/AccessibleCaret.rst
+//
+class AccessibleCaretEventHub : public nsIReflowObserver,
+ public nsIScrollObserver,
+ public nsSupportsWeakReference {
+ public:
+ explicit AccessibleCaretEventHub(PresShell* aPresShell);
+ void Init();
+ void Terminate();
+
+ MOZ_CAN_RUN_SCRIPT
+ nsEventStatus HandleEvent(WidgetEvent* aEvent);
+
+ // Call this function to notify the blur event happened.
+ MOZ_CAN_RUN_SCRIPT
+ void NotifyBlur(bool aIsLeavingDocument);
+
+ NS_DECL_ISUPPORTS
+
+ // nsIReflowObserver
+ MOZ_CAN_RUN_SCRIPT_BOUNDARY
+ NS_IMETHOD Reflow(DOMHighResTimeStamp start, DOMHighResTimeStamp end) final;
+ MOZ_CAN_RUN_SCRIPT_BOUNDARY
+ NS_IMETHOD ReflowInterruptible(DOMHighResTimeStamp start,
+ DOMHighResTimeStamp end) final;
+
+ // Override nsIScrollObserver methods.
+ MOZ_CAN_RUN_SCRIPT_BOUNDARY
+ virtual void ScrollPositionChanged() override;
+ MOZ_CAN_RUN_SCRIPT
+ virtual void AsyncPanZoomStarted() override;
+ MOZ_CAN_RUN_SCRIPT
+ virtual void AsyncPanZoomStopped() override;
+
+ // Base state
+ class State;
+ State* GetState() const;
+
+ MOZ_CAN_RUN_SCRIPT
+ void OnSelectionChange(dom::Document* aDocument, dom::Selection* aSelection,
+ int16_t aReason);
+
+ bool ShouldDisableApz() const;
+
+ protected:
+ virtual ~AccessibleCaretEventHub() = default;
+
+#define MOZ_DECL_STATE_CLASS_GETTER(aClassName) \
+ class aClassName; \
+ static State* aClassName();
+
+#define MOZ_IMPL_STATE_CLASS_GETTER(aClassName) \
+ AccessibleCaretEventHub::State* AccessibleCaretEventHub::aClassName() { \
+ static class aClassName singleton; \
+ return &singleton; \
+ }
+
+ // Concrete state getters
+ MOZ_DECL_STATE_CLASS_GETTER(NoActionState)
+ MOZ_DECL_STATE_CLASS_GETTER(PressCaretState)
+ MOZ_DECL_STATE_CLASS_GETTER(DragCaretState)
+ MOZ_DECL_STATE_CLASS_GETTER(PressNoCaretState)
+ MOZ_DECL_STATE_CLASS_GETTER(ScrollState)
+ MOZ_DECL_STATE_CLASS_GETTER(LongTapState)
+
+ void SetState(State* aState);
+
+ MOZ_CAN_RUN_SCRIPT
+ nsEventStatus HandleMouseEvent(WidgetMouseEvent* aEvent);
+ MOZ_CAN_RUN_SCRIPT
+ nsEventStatus HandleTouchEvent(WidgetTouchEvent* aEvent);
+ MOZ_CAN_RUN_SCRIPT
+ nsEventStatus HandleKeyboardEvent(WidgetKeyboardEvent* aEvent);
+
+ virtual nsPoint GetTouchEventPosition(WidgetTouchEvent* aEvent,
+ int32_t aIdentifier) const;
+ virtual nsPoint GetMouseEventPosition(WidgetMouseEvent* aEvent) const;
+
+ bool MoveDistanceIsLarge(const nsPoint& aPoint) const;
+
+ void LaunchLongTapInjector();
+ void CancelLongTapInjector();
+
+ MOZ_CAN_RUN_SCRIPT_BOUNDARY
+ static void FireLongTap(nsITimer* aTimer, void* aAccessibleCaretEventHub);
+
+ void LaunchScrollEndInjector();
+ void CancelScrollEndInjector();
+
+ MOZ_CAN_RUN_SCRIPT_BOUNDARY
+ static void FireScrollEnd(nsITimer* aTimer, void* aAccessibleCaretEventHub);
+
+ // Member variables
+ State* mState = NoActionState();
+
+ // Will be set to nullptr in Terminate().
+ PresShell* MOZ_NON_OWNING_REF mPresShell = nullptr;
+
+ UniquePtr<AccessibleCaretManager> mManager;
+
+ WeakPtr<nsDocShell> mDocShell;
+
+ // Use this timer for injecting a long tap event when APZ is disabled. If APZ
+ // is enabled, it will send long tap event to us.
+ nsCOMPtr<nsITimer> mLongTapInjectorTimer;
+
+ // Last mouse button down event or touch start event point.
+ nsPoint mPressPoint{NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE};
+
+ // For filter multitouch event
+ int32_t mActiveTouchId = kInvalidTouchId;
+
+ // Flag to indicate the class has been initialized.
+ bool mInitialized = false;
+
+ // Flag to avoid calling Reflow() callback recursively.
+ bool mIsInReflowCallback = false;
+
+ static const int32_t kMoveStartToleranceInPixel = 5;
+ static const int32_t kInvalidTouchId = -1;
+ static const int32_t kDefaultTouchId = 0; // For mouse event
+};
+
+// -----------------------------------------------------------------------------
+// The base class for concrete states. A concrete state should inherit from this
+// class, and override the methods to handle the events or callbacks. A concrete
+// state is also responsible for transforming itself to the next concrete state.
+//
+class AccessibleCaretEventHub::State {
+ public:
+ virtual const char* Name() const { return ""; }
+
+ MOZ_CAN_RUN_SCRIPT
+ virtual nsEventStatus OnPress(AccessibleCaretEventHub* aContext,
+ const nsPoint& aPoint, int32_t aTouchId,
+ EventClassID aEventClass) {
+ return nsEventStatus_eIgnore;
+ }
+
+ MOZ_CAN_RUN_SCRIPT
+ virtual nsEventStatus OnMove(AccessibleCaretEventHub* aContext,
+ const nsPoint& aPoint,
+ WidgetMouseEvent::Reason aReason) {
+ return nsEventStatus_eIgnore;
+ }
+
+ MOZ_CAN_RUN_SCRIPT
+ virtual nsEventStatus OnRelease(AccessibleCaretEventHub* aContext) {
+ return nsEventStatus_eIgnore;
+ }
+
+ MOZ_CAN_RUN_SCRIPT
+ virtual nsEventStatus OnLongTap(AccessibleCaretEventHub* aContext,
+ const nsPoint& aPoint) {
+ return nsEventStatus_eIgnore;
+ }
+
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnScrollStart(AccessibleCaretEventHub* aContext) {}
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnScrollEnd(AccessibleCaretEventHub* aContext) {}
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnScrollPositionChanged(AccessibleCaretEventHub* aContext) {}
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnBlur(AccessibleCaretEventHub* aContext,
+ bool aIsLeavingDocument) {}
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnSelectionChanged(AccessibleCaretEventHub* aContext,
+ dom::Document* aDoc, dom::Selection* aSel,
+ int16_t aReason) {}
+ MOZ_CAN_RUN_SCRIPT
+ virtual void OnReflow(AccessibleCaretEventHub* aContext) {}
+ virtual void Enter(AccessibleCaretEventHub* aContext) {}
+ virtual void Leave(AccessibleCaretEventHub* aContext) {}
+
+ explicit State() = default;
+ virtual ~State() = default;
+ State(const State&) = delete;
+ State& operator=(const State&) = delete;
+};
+
+} // namespace mozilla
+
+#endif // mozilla_AccessibleCaretEventHub_h